Quaternary ammonium salts of substituted phenanthrolines



United States Patent 3,338,906 QUATERNARY AMMONIUM SALTS 0F SUBSTI- TUTED PHENANTHROLINES Francis Patrick Dwyer, deceased, late of Griffith, New

South Wales, Australia, by Lola Mary Dwyer, executrix, Griflith, New South Wales, Australia, and Roy Douglas Wright, Parkville, Victoria, and Albert Shulman, Prahran, Victoria, Australia, assignors to The Australian National University, Acton, Canberra, New South Wales, Australia, a corporation of Australia No Drawing. Filed May 24, 1963, Ser. No. 283,110 Claims priority, application Australia, Jan. 26, 1960, 56,849/ 60 8 Claims. (Cl. 260-286) This application is a continuation-in-part of application Ser. No. 84,533, filed Jan. 24, 1961.

This invention relates to new mono N-alkylated derivatives of substituted 1,10-phenanthrolines. The new mono N-alkylated derivatives are quaternary ammonium base cations, with which are associated the anions of inorganic acids, e.g., chloride, sulfate, or of organic acids, e.g., maleate, benzoate. In this specification, the numbering of the 1,10-phenanthroline hereinafter is in agreement with ring No. 1954, page 264, of The Ring Index, A. M. Patterson and L. T. Capell, Monograph Series, published 1940 by Rheinhold Publishing Corporation.

According to the invention there is provided quaternary ammonium salts of the structure wherein B is a cation of the structure s wherein R is selected from the group consisting of alkyl radicals having up to six carbon atoms and benzyl; wherein R R R R R R R and R represent a mixture of hydrogen and substituent radicals selected from the group consisting of alkyl, phenyl, tolyl and xylyl; provided that when alkyl substituent radicals are present, there are two to four of such radicals in said R positions and having a total of two to six carbon atoms, with hydrogen in the remaining R positions; and further provided that when a substituent radical selected from phenyl, t-olyl and xylyl is present, there is from one to two of such radicals in the R R R and R positions, with hydrogen in the remaining R positions; wherein X is an anion of an acid selected from inorganic and organic acids; and wherein m is the valency of the anion.

The new quaternary ammonium salts of the invention can be prepared by the method which comprises reacting an appropriately substituted 1,10-phenanthroline base with an alkylating agent which provides the components R and X as specified, and recovering the desired salt. In carrying out this method, the reaction is brought about usually merely by mixing the reaction components, however, heat may assist in completing the reaction. The components may be mixed alone or in the presence of a solvent such as alcohol or methanol. For volatile alkylatin-g agents a closed system such as a sealed reaction tube is required to prevent loss of the reagent, if heat is used. The product can be isolated by the usual methods such as dissolving the reaction mixture in a solvent, filtering, concentrating and precipitating.

The most suitable alkylating agents are the alkyl halides. Of these the iodides are most reactive, but the less expensive chlorides and bromides can be used. Diethyl and dimethyl sulfates can be used satisfactorily. Examice ples of alkylating agents are methyl iodide, butyl bromide, dimethyl sulfate. These alkylating agents result in a product in which the anion is a halogen or sulfate. Other anions may be substituted by standard procedures using for example ion exchange resins or double decomposition reactions, for example, the saccharate anion may be imposed as it has value in increasing the water-solubility of the compounds; alternatively, anions such as stearate, oleate, and the like may be imposed in order to decrease water-solubility of the compounds. A representative list of anions include sulfate, chloride, bromide, iodide, phosphate, nitrate, acetate, sulfamate, citrate, lactate, maleate, malate, succinate, tartrate, cinnamate, benzoate, gluconate, ascorbate, saccharate, stearate and oleate.

Compounds in accordance with the invention are useful as therapeutic agents for the treatment of animal and plant diseases induced by a Wide variety of organisms. In particular, the compounds are valuable for the treatment of various topical infections in humans, in the treatment of :bovine mastitis, in the treatment of plant fungal conditions, and as anthelminthics. These compounds have value in being active against a Wide variety of microorganisms, i.e., Gram-positive organisms, Gram-negative organisms, Acid-fast organisms, pathogenic fungi, yeast (Saccharomyces cerevisiae) and virus (influenza). The compounds are stable in solu.

, tion and are non-irritant at very high concentrations (1 to 2% solutions) to skin surfaces, (mucuous surface (eye, ear, nose, throat) mucuous cavities (vagina, gut, bladder) and subcutaneous tissues (muscles, bone).

In the treatment of bovine mastitis, the present compounds are effective clinically in resolving acute and chronic infections due to (Group B) Streptococci .or Staphylococcus pyogenes which have proved refractory to the antibiotics in current use for the purpose.

In the treatment of plant diseases due to microorganisms, in particular, plant fungi and nematodes, tests have been conducted against the plant fungi Venluria inaequalis and Phytophthora infestzms, and against the plant nematodes Panqgrellus redivivis and Meloz'dogune incognita. Vemuria inaequalis causes Black Spot on apples; Phytophtlrora infestans causes Late Blight of tomatoes and potatoes; and the nemat-odes cause root infestations of plants. Excellent control of these organisms, has been obtained with several of the present compounds which have been tested.

We believe that the specified mono N-alkylated derivatives, of 1,10-phenanthroline according to the invention, .exert their therapeutic action by their capacity to bind or attach themselves to essential biological sites (enzymes and proteins) by electrostatic and/ or Van der Waals .forces. The binding of the compounds herein to the biologically active sites, whether on the surface or within cells, by Van der Waals forces is a most important .consideration. This is related not only to the geometrical shape of the site but also to the surface area of such compounds. The surface area may be controlled by the amount and nature of ring substitution of the 1,10-phenanthroline bases. N-alkylation of the substituted 1,10-phenanthroline base confers one positive charge on the base and transforms them into cations. We consider that the cation is attracted and partly held, at least, to the biological site because that site has some negative charge, i.e., some anionic charge. The group used for quaternisation of the nitrogen atom has an important effect on the penetrability of the drug.

Ring substitution of the prime base 1,10-phenanthroline with alkyl groups may, as specified above, occur in two to four of the 2-, 3-, 4-, 5-, 6-, 7-, 8- and 9-positions of substitution with similar or dissimilar substituents totalling from two to six carbon atoms. Multi-substitution 3 with alkyl groups as specified is favoured, the triand tetra-substituted derivatives being preferred. We have found that tetra-alkyl substitution, particularly 3,4,7,8- tetramethyl and 2,4,7,9-tetramethyl and 3,5,6,8-tetrameth 4 C=Clostridium welchz'i D=Escherichia coli E=Proteus vulgaris F=Microsprum canis yl substitution, contribute to high activity in combatting G=Tri0h0phyf0n mentogrophytes bacterlal infections in humans, symmetrical substitution H=Trichophyton rubrum being preferred; however, di'methyl substitution in the 2- I=Trich0phyton sulphureum' and 9-positions, or, tetramethyl substitution in the 3-, 4-, J=Epiderm0phyt0n flaccocum 5- and 6-positions also yield highly useful compounds. K=Carrdida albicans (solid medium) Similarly, substitution of the prime base, 1,10-phenanthroline with phenyl, tolyl and xylyl groups may, as specig z f agamst the FE -59 i g j fied above, occur in one or two of the 4-, 5-, 6- and 7- 1 can-1e m f f 1 16s 0 positions of substitution, and preferably is symmetrical g Dlfco g fi z z 3 when there are two such substituents. Orse Serum 6 es compoun n 6 case 0 Some representative examples of compounds prepared f i 2 drops of a Sterile 10% sodlum in accordance with the invention are as follows: throglycollate solution were added aseptically to the medium. The inoculum in each case was a drop (0.02 ml.) (1) f 3 i of an 18 hour culture of the organism and the incubation bromlde period at 37 C. was 48 hours. The tests against the Y i i -p 20 pathogenic fungi were carried out on 4% malt agar slopes sulfate n containing the test compound. In the case of compounds (3) l'fienzyl'4i7'dlmethyl'lAmphenanthmhmum sparingly soluble in Water but soluble in ethanol, a single chlonde test was carried out against Candida albicans in 4% malt Y -P lf i extract medium (2 ml.). The inoculum in the solid me- P PY P Y J dium was a small piece of fungus and in the liquid mebromlde dium one drop (0.02 ml.) of a 48 hour culture of the These and other compounds a di t th i ti organism. The incubation period in the solid medium was can be prepared as illustrated in the following practical 28 y at and ill the liquid medium 48 hours at examples. The starting materials, i.e. the substituted 1,10- Q phenanthroline base and the alkyl halides are either 30 The therapeutic Value Y i i i known or can b prepared b d d procedures methyl-1,IO-phenanthrolinium iodide in the treatmentof AMPLE 1 acute and chronic staphylococcal and streptococcal bovlne EX mastitis was investigated. All chronic infections had failed 1-benzyl-4,7-dimethyl-1,IO-phenanthrolinium chloride to respond to penicillin therapy. Local treatment with 4,7-dimethyl-1,IO-phenanthroline monohydrate, (1 g.) 5 each compound twlcdally In a p f is heated in a sealed tube t 100 Q i h b l chloride Wax base) was glven, and the chemical and bacteriological (12 ml.) for 16 hours. The reaction mixture is cooled fi il of tgiadmmstratlonlwag g fi g case with ice and 25 ml. of ether added. The oil solid is t 6 con Hons were r650 e SPecl e separated by filtration, dissolved in 10 ml. (if boiling resolvgd the P Q water, treated with activated charcoal, and filtered. The 40 g i g 'N' fg xg i ig g ae ueous solution is eva orated in an oven at 90 C. me y p enan romlum 1 e S 5 finally dried in a vacgum dessicator over phosphorus Venturia inaequalis and Phytophthora infestans. The compentoxide. The resultant material has a melting point of Pound gave excellent funglcldal result? at a concentra" 94 tion of 100 ppm. against both organisms.

EXAMPLE 2 Application of the present compounds in the fields of animal and plant therapy is effected by means of a 1WWW-3,47i8-feim'gefhyl-l,1o-phenamhmlmmm carrier or diluent for the compound. For example, in the odlde therapeutic treatment of bacterial infections in humans, 3,4,7,8-tetramethyl-1,10-phenanthroline monohydrate the compound is applied in forms such as saline solu- (0.5 g.) is heated at 100 C. in a sealed tube with methyl tions, creams, lotions, nose or eye or ear drops, pessaries, iodide (0.8 ml.) for one-half hour. The crystals obtained suppositories, tablets, lozenges and the like. A dermaare twice recrystallised from methanol. The resultant matological or vaginal cream may contain 10 mgm./ gm. of terial has amelting point of 225 C. the compound in the cream base; a lotion may contain Results of bacteriostatic and fungistatic tests with the 10 mgmjml. of the compound; a saline solution may compounds listed above as representative Examples 1, 2, contain 5-10 mgm./ml. of the compound; nose drops may 3 and 4 of the compounds herein, with respect to incontain 10 mgm./ml. of the compound in saline; eye hibitory concentration against the series of microorgandrops may contain 4 mgm./ml. of the compound in isms listed below, expressed in micrograms/milliliter in saline; ear drops may contain 10 mgm./ml. of the comthe medium further specified below, are as follows: pound in propylene glycol; 5 grams pessa'ries and sup- Test A B o D E F G H I J K Compound In the above table the blank spaces in columns F to K means that no test details are available, whereasthe blank gg a g i g fisfi g y g' g g figg g :5 spaces In columns and E i that the Speclfied compound. Likewise, in veterinary treatments, such as pounds where mactwe at 100 mlcrograrps/{nl' The coded bovine mastitis, the compounds are applied in a suitable test orgamsms correspond to the followmg' carrier media, such as paraffin and wax base, whilst in A=Staphyloc0ccus pyogenes (Oxford) veterinary anthelminthic preparations, the compounds are B=Strep1QCOCCuS pyogenes (Group A) i applied conveniently as a drench, preferably as an aqueous solution or aqueous suspension of the compound, depending upon its water solubility. When applied as plant fungicides or as plant virocides, the water-insoluble compounds conveniently are formulated as dispersible powders, whilst the Water-soluble compounds are formulated as aqueous solutions, however, concentrate-forms of the compounds in organic solvent solutions may be prepared for further use, such as preparation of aqueous emulsions of the compounds, and, any of these formulations may include wetting agents and/or other materials of assistance in formulating the compounds or in their end use.

We claim:

1. A quaternary ammonium salt of the formula wherein 1 is alkyl of up to four carbon atoms, R R R and R are hydrogen and from one to two of R R R and R are selected from the class consisting of phenyl, tolyl and xylyl; wherein X is a halide anion of the class consisting of chloride, bromide and iodide.

3. l-butyl 3,4,7,8-tetramethyl-1,10-phenanthro1inium bromide.

4. l-methyl 3,4,7,8-tetran1ethy1-1,1O-phenanthrolinium sulfate.

5. l-benzyl 4,74iimethyl- 1,10-phenanthrolinium chloride.

6. l-methyl 5 phenyl-l,IO-phenanthrolinium bromide.

7. l-isopropyl 4,7 diphenyl-l,IO-phenanthrolinium bromide.

8. l-methyl 3,4,7,8-tetramtthyl-1,10-phenanthro1inium iodide.

References Cited UNITED STATES PATENTS 2,617,753 11/1952 Gysin et a1. 260288 X 2,640,830 6/1953 Druey 260288 2,651,636 9/1953 Wheeler 260288 2,809,146 10/1957 Osborn 167-33 3,147,182 9/1964 Masci 16733 OTHER REFERENCES Frear, Chemistry of the Pesticides, Van Nostrand, 3rd ed. 1955, pages 301-2 relied on.

Halcrow et al., J. Chem. Soc. (London) 1946, pages -157.

Karrer et al., Helv. Chim Acta, vol. 31, pages 786-794 (788 relied on).

ALEX MAZEL, Primary Examiner. H. JILES, Examiner.

D. G. DAUS, Assistant Examiner. 

1. A QUATERNARY AMMONIUM SALT OF THE FORMULA
 2. A QUATERNARY AMMONIUM SALT OF THE FORMULA 